1. Field of the Invention
The present invention relates to an electronic device, and more specifically to an electronic device such as a ladder filter or a capacitive oscillator which is made by encasing stacked electronic elements and terminals within a molded case.
2. Description of Related Art
According to a conventional way of producing an electronic device such as a ladder filter or a capacitive oscillator, piezoelectric elements and terminals are initially arranged in a resin frame to be formed as a unit and this unit is then mounted inside a shallow box-shaped case. This conventional method of production has many drawbacks. Firstly, a resin frame is necessary and the work of assembly is complicated. Secondly, since the connecting portions of the terminals protrude from a side of the case, the device will have to be mounted on a circuit board with this side wall pointing downward, making its mounting unstable.
In another well-known way of making an electronic device, a terminal for connecting electronic elements arranged inside the device with an external appliance is inserted into a mold of a resin case so that the terminal will be fixed to the case when the resin is molded into the case. The terminal has a projection which will be a contact point with the electronic elements, and this projection makes it difficult to release the case and terminal from the mold. If a cavity is made in the mold at a place where the terminal will be put, melted resin will flow into the cavity. If there is anything attached to the mold at the inlet of the cavity in order to prevent the resin from flowing into the cavity, the projection of the terminal is likely to be caught thereon when the case and terminal are to be released from the mold.